Genetic gains are dependent on the incorporation of new, unique and useful genetic diversity to the breeding programs. Finding and incorporating new genes into productive genetic pools cannot be accomplished without a sustained effort. New sources of germplasm must have yield potential with other useful traits so that breeders can be encouraged to use sources of new genetic diversity. The wide genetic diversity of the crop has been maintained, characterized and classified in several germplasm banks. For this germplasm to be useful an international project for evaluation took place, denominated the Latin American Maize Project (LAMP), in which 12 countries were involved. Most selected LAMP germplasm are unadapted to temperate locations and require a conversion and selective adaptation to the major corn growing areas of the U.S. To accomplish this, an unprecedented public/private research effort to utilize the genetic diversity from LAMP and other elite exotic sources was initiated as the Germplasm Enhancement of Maize project (GEM). This project is a unique example of collaboration in which public entities and private seed companies work together with the objective of increasing the productivity and genetic diversity of maize grown in the U.S. The results indicate that alleles from exotic sources can be combined with genes of elite Corn Belt lines to generate materials useful in breeding programs. Several lines were released from GEM and have been used by the cooperators. The Tropical Germplasm Enhancement Project of the Pioneer Hi-bred International, Inc. was established to identify and introgress useful alleles from tropical germplasm into elite lines of the company. The exchange of germplasm of elite lines within U.S.A. and across regions took place developing some new germplasm to be used by breeders.